{
  "type": "File",
  "start": 0,
  "end": 48,
  "loc": {
    "start": {
      "line": 1,
      "column": 0
    },
    "end": {
      "line": 1,
      "column": 48
    }
  },
  "program": {
    "type": "Program",
    "start": 0,
    "end": 48,
    "loc": {
      "start": {
        "line": 1,
        "column": 0
      },
      "end": {
        "line": 1,
        "column": 48
      }
    },
    "sourceType": "module",
    "interpreter": null,
    "body": [
      {
        "type": "VariableDeclaration",
        "start": 0,
        "end": 48,
        "loc": {
          "start": {
            "line": 1,
            "column": 0
          },
          "end": {
            "line": 1,
            "column": 48
          }
        },
        "declarations": [
          {
            "type": "VariableDeclarator",
            "start": 6,
            "end": 47,
            "loc": {
              "start": {
                "line": 1,
                "column": 6
              },
              "end": {
                "line": 1,
                "column": 47
              }
            },
            "id": {
              "type": "Identifier",
              "start": 6,
              "end": 8,
              "loc": {
                "start": {
                  "line": 1,
                  "column": 6
                },
                "end": {
                  "line": 1,
                  "column": 8
                },
                "identifierName": "fn"
              },
              "name": "fn"
            },
            "init": {
              "type": "ArrowFunctionExpression",
              "start": 11,
              "end": 47,
              "loc": {
                "start": {
                  "line": 1,
                  "column": 11
                },
                "end": {
                  "line": 1,
                  "column": 47
                }
              },
              "returnType": {
                "type": "TypeAnnotation",
                "start": 26,
                "end": 41,
                "loc": {
                  "start": {
                    "line": 1,
                    "column": 26
                  },
                  "end": {
                    "line": 1,
                    "column": 41
                  }
                },
                "typeAnnotation": {
                  "type": "GenericTypeAnnotation",
                  "start": 28,
                  "end": 41,
                  "loc": {
                    "start": {
                      "line": 1,
                      "column": 28
                    },
                    "end": {
                      "line": 1,
                      "column": 41
                    }
                  },
                  "typeParameters": {
                    "type": "TypeParameterInstantiation",
                    "start": 35,
                    "end": 41,
                    "loc": {
                      "start": {
                        "line": 1,
                        "column": 35
                      },
                      "end": {
                        "line": 1,
                        "column": 41
                      }
                    },
                    "params": [
                      {
                        "type": "VoidTypeAnnotation",
                        "start": 36,
                        "end": 40,
                        "loc": {
                          "start": {
                            "line": 1,
                            "column": 36
                          },
                          "end": {
                            "line": 1,
                            "column": 40
                          }
                        }
                      }
                    ]
                  },
                  "id": {
                    "type": "Identifier",
                    "start": 28,
                    "end": 35,
                    "loc": {
                      "start": {
                        "line": 1,
                        "column": 28
                      },
                      "end": {
                        "line": 1,
                        "column": 35
                      },
                      "identifierName": "Promise"
                    },
                    "name": "Promise"
                  }
                }
              },
              "id": null,
              "generator": false,
              "async": true,
              "params": [
                {
                  "type": "Identifier",
                  "start": 18,
                  "end": 25,
                  "loc": {
                    "start": {
                      "line": 1,
                      "column": 18
                    },
                    "end": {
                      "line": 1,
                      "column": 25
                    },
                    "identifierName": "a"
                  },
                  "name": "a",
                  "optional": true,
                  "typeAnnotation": {
                    "type": "TypeAnnotation",
                    "start": 20,
                    "end": 25,
                    "loc": {
                      "start": {
                        "line": 1,
                        "column": 20
                      },
                      "end": {
                        "line": 1,
                        "column": 25
                      }
                    },
                    "typeAnnotation": {
                      "type": "AnyTypeAnnotation",
                      "start": 22,
                      "end": 25,
                      "loc": {
                        "start": {
                          "line": 1,
                          "column": 22
                        },
                        "end": {
                          "line": 1,
                          "column": 25
                        }
                      }
                    }
                  }
                }
              ],
              "body": {
                "type": "BlockStatement",
                "start": 45,
                "end": 47,
                "loc": {
                  "start": {
                    "line": 1,
                    "column": 45
                  },
                  "end": {
                    "line": 1,
                    "column": 47
                  }
                },
                "body": [],
                "directives": []
              }
            }
          }
        ],
        "kind": "const"
      }
    ],
    "directives": []
  }
}